Orbit does allow for anonymous browsing. I'm somewhat sure you still connect to a list of proxies and go from there. Your information isn't as much stored on a proxy as it is passing through it, and as such tor exit nodes would still be able to eavesdrop on you. Remember, Tor is more for anonymity than security. With a vpn and tor, it should go as you -> vpn -> entry node -> relay node -> exit node -> internet. Either way, if you use your name, log on to facebook or whatever, there's no point to using an anonymous browsing app. That just connects you to the name you're connecting to either way, with the added problem of your information being on tor nodes (such as username/passwords). A vpn won't change that if you're still using tor.

Another point is, it's not really worth going through tor and a vpn on a cellphone. That just takes more time and data usage than you need to bother with.